For centuries asphalt and other bituminous products have been used to provide waterproofing and protective coverings and coatings for roofs, foundations, and the like; resilient, weather resistant pavings; and sealants useful in a wide variety of applications. And for as long as asphalts have been used for such purposes it has been found necessary from time to time to repair the installations of which they form part. A particularly vexing annoyance has been that those times at which the need for repair is made most apparent, and at which the need for repairs is most sorely immediate, are those very times when it is both most difficult and least convenient to make them: for example, when it is raining and/or temperatures are below freezing. Both moisture and cool temperatures make it very difficult to apply or install asphalt compounds, including mastics and other asphalts used in the repair of existing roofs, because asphalts typically do not adhere to damp or wet surfaces and water and because they become highly viscous and even solid at reduced temperatures.
In addition, it has long been recognized that oxidizing the asphalts used in each of the above mentioned applications produces results far superior to those achieved by using unoxidized, straight-run or "flux" asphalts. Among other effects, the oxidization of asphalt raises its softening point--which in most roofing, sealing, and waterproofing applications is desirable. For example, it is desirable to use an asphalt having a softening point in excess of 100.degree. F. on roofs exposed to warm summer sun, which can cause temperatures in the asphalt to exceed the typical 70.degree. softening point of unoxidized asphalts by a considerable margin. Yet the oxidation of asphalt and the consequential elevation of its softening point aggravates the difficulty of applying the asphalt--with a higher softening point, the asphalt is even stiffer then before at any given temperature. In the past, the solution to the problem of repairing leaks in asphalt roofing installations in inclement weather, using mastics and the like, has been addressed, as best may be, through the mixing of straight-run (unoxidized) asphalts, with their inferior weather-resistant qualities and low softening points, with mineral spirits to form cutback asphalts. The mixing of asphalt with mineral spirit solvents to form cutback asphalts has the effect of lowering the softening point of the asphalt, so that it can be applied at relatively low temperatures without heating. Once the cutback has been installed, the mineral spirit cutback agent evaporates, leaving behind only the asphalt base, together with any other added non-volatile substances such as bulk and insulation fillers. Yet even the use of mineral spirit solvents as cutback agents can lower the softening point, or the viscosity, of an asphalt so far--at least, that is, when acceptable amounts of the solvent are used. In order to make most asphalt soft enough to be applied in cold temperatures, in excess of 60% mineral spirits (by weight) must typically be used, leaving a solids (asphalt) content of 40% or less. This reduces the solid (asphalt) content of the cutback to unacceptably low levels and reduces the viscosity, durability, and weather resistance of the residual asphalt coating. Indeed, mineral spirit cutback asphalts used today generally fail to meet accepted quality standards published by the American Society of Testing Materials (ASTM). The use of oxidized asphalts, with their elevated softening points and increased viscosity, has only aggravated the problem. Even more mineral spirits are used, leaving behind even less solids content having even worse residual properties. And neither cutback nor straight paving grade asphalts have greater affinity for water than any other asphalts, so that the use of such asphalts in wet conditions to repair, for example, leaky roofs has been unsatisfactory. Thus attempts to utilize the superior weather-resistant qualities available through the use of fully oxidized asphalts (sometimes called "air blown" asphalts in the industry) as bases for the cutback asphalts have consistently resulted in mixtures having either melting or softening points well above the point at which such asphalts can be effectively applied in cold temperatures or far too high a solvent content, or both.
Other attempts have been made. For example, U.S. Pat. No. 5,362,316 to Paradise discloses a composition comprising asphalt, coal tar, elastomers, and a terpene solvent; while U.S. Pat. No. 5,618,340 and 5,622,554 to Krogh et al. disclose a roof-coating compositions comprising alkylated fatty amines and alkoxylated ether amine surfactants. None of these attempts, however, teaches a means for producing mastics, coatings, or sealants which enjoy the benefits of using oxidized asphalts.
Thus there exists a need for an asphalt roofing, waterproofing, and sealing compound enjoying the benefits of a fully oxidized asphalt base and suitable for use in cold weather and in damp or wet conditions, having acceptable viscosity over a broad range of temperatures and an acceptable solids content, and which meets accepted quality standards such as those published by the ASTM.